Vetting Against the Odds

For law enforcement officials and the public at large, the investigation of Omar Mateen, the gunman behind the June 12 mass shooting in Orlando, has raised as many questions as it has answered. What were his motivations? What was the state of his mental health? How did it happen that the FBI, which twice investigated Mateen, did not have him under active surveillance at the time of the attack? And why was he still employed in good standing as an armed security officer with G4S, the world's largest security services provider, at the time of the attack? The answer to this last question, at least, has already surfaced. By GS4's own account, Mateen underwent a pre-employment screening in 2007, including criminal background checks, credit checks and, according to one report, a psychometric test. The company reinvestigated Mateen for cause in 2013, around the same time that the FBI was looking...